Hello Daniel-san
Thanks for clarifying the Shimbashi station for me! I'm still struggling with a suitable route from Hakuba. I can see on HyperDia that we can get a train from Hakuba to Matsumoto, but then to get into Shinjuku, the train routes all seem to backtrack up to Nagano. Is there any direct JR train from Matsumoto to 'anywhere in Tokyo' that we can then get a train to Shimbashi?